There are literally dozens of online vendors. You need to know what you want. Your H2 has a Pollack 7 pin jack, so your cable have a Pollack 7 pin plug. What you need on the other end of the harness is a connector (probably a plug of some type) that will mate with your trailer (probably a jack of that same type).
http://www.mooretruckaccessories.com..._Adaptors.html